The present invention relates to anti-microbial silver oxide formulations.
Silver and various silver derivatives are known to have anti-microbial properties. Silver(II) oxide is known to be more effective than silver(I) oxide. Commercial applications of such products include impregnated bandages, mold-free and odor-free textiles, and various kinds of skin creams. In addition, there exist several oral medicines that utilize silver as an active ingredient, including anti-smoking lozenges containing silver acetate (AgC2H3O2), breath mints coated with silver, and silver nitrate solutions for treating gum disease.
One particularly effective group of silver derivatives is the group of silver oxides. Of the silver oxides, AgO is known to be more effective than Ag2O.
It was reported by U.S. Pat. No. 6,258,385 to Antelman, which is incorporated by reference for all purposes as if fully set forth herein, that                the effects of the electron transfer involved with respect to the tetroxide, phenomenally, rendered it a more powerful germicide than other silver entities . . . . The oligodynamic properties of these entities may be summarized as follows, which is referred to as the Horsfal series:Ag4O4>Ag(III)>Ag(II)>>>>Ag(I).        
Skin creams containing silver(II) oxide have been reported to be efficacious in treating various medical conditions, including genital herpes, oral herpes, vaginitis, vaginal yeast infections, foot and nail fungus, burns, warts, and skin infections. These skin formulations are characterized by their creaminess and ease of application, which, inter alia, enables the polyvalent silver oxide to intimately contact the skin surface.
Disadvantageously, however, the various forms of silver oxide, and silver(II) oxide in particular, are dark gray or charcoal gray powders, and are thus extremely hard to hide within white creams used in various cosmetic or pharmaceutical topical applications. Moreover, the dark silver oxide particles may stain skin and clothing.
Chronic wound care is a critical and growing issue in healthcare systems. A chronic wound may be defined as a wound that shows no sign of appreciable healing within 2-3 months. Chronic wounds such as skin ulcers are the most common complication of diabetes, which has been termed a “Silent Epidemic”. Above and beyond their economic burden on healthcare systems, chronic wounds represent a debilitating problem having significant clinical and social ramifications. Chronic wounds may be non-responsive or poorly responsive to various known treatments. Consequently, such chronic wounds may become severely infected, leading to gangrene and amputations.
While some advances have been made in the treatment of wounds, both chronic and acute, we believe there is a need for further improvements in formulating stable, efficacious topical silver oxide formulations, and the subject matter of the present disclosure and claims is aimed at fulfilling this need.